What refers to the change in the body's chemical composition that occurs after death?

The term that refers to the change in the body's chemical composition after death is known as postmortem chemical change. This process encompasses a variety of biochemical transformations that occur as the body begins to break down. After death, cells lose their blood supply and oxygen, leading to anaerobic metabolism and the subsequent production of various chemicals. These changes can significantly alter the body's internal environment.

Postmortem chemical changes include processes like autolysis, where enzymes within cells break down tissues, and putrefaction, which is the action of bacteria and microorganisms leading to further tissue decomposition. Understanding these changes is crucial in forensic science and mortuary practices because they can be indicative of the time since death and overall conditions surrounding it.

The other options, while they may relate to processes occurring after death, do not specifically capture the comprehensive shifts in chemical makeup that occur during the postmortem period. Thus, postmortem chemical change is the most accurate term to describe this phenomenon.